1. Field of the Invention
The present invention relates to an image forming apparatus provided with a cleaning device used to remove residual toner from the surface of an image-bearing member such as a photosensitive member, dielectric member or the like in electrophotographic copiers, electrophotographic facsimile machines, electrophotographic printers and the like.
2. Description of the Related Art
Conventional image forming apparatuses are known wherein a photosensitive member provided with an image-bearing member on the surface thereof is charged, and the surface of said photosensitive member is optically exposed in accordance with image information to form an electrostatic latent image which is then developed as a toner image by a developing device, and said toner image is transferred onto a paper sheet, and the residual toner remaining on the surface of the image-bearing member is removed therefrom. In such image forming apparatuses, a precleaning charger is provided in front of the cleaning device to improve the cleaning characteristics by discharging the charge of the residual toner and weakening the electrostatic attractive force of the photosensitive member. It has been proposed that a precleaning charger may be controlled by controlling the output of the precleaning charger in accordance with the amount of toner adhered to the image-bearing member after the image transfer as disclosed, for example, in Japanese Unexamined Patent Application No. SHO 64-68783, or the charge of the residual toner remaining on the surface of the image-bearing member may be set to either positive or negative by means of said precleaning charger, as disclosed in Japanese Unexamined Patent Application No. HEI 2-48683.